Commit 8d86e373 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Clean up helpers xdr_set_iov() and xdr_set_page_base() 



Allow xdr_set_iov() to set a base so that we can use it to set the
cursor to a specific position in the kvec buffer.

If the new base overflows the kvec/pages buffer in either xdr_set_iov()
or xdr_set_page_base(), then truncate it so that we point to the end of
the buffer.

Finally, change both function to return the number of bytes remaining to
read in their buffers.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 2b1f83d1

net/sunrpc/xdr.c

+19 −17
Original line number Diff line number Diff line
@@ -970,18 +970,21 @@ void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int b 
}

EXPORT_SYMBOL_GPL(xdr_write_pages);



static void xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov,

		unsigned int len)

static unsigned int xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov,

				unsigned int base, unsigned int len)

{

	if (len > iov->iov_len)

		len = iov->iov_len;

	xdr->p = (__be32*)iov->iov_base;

	if (unlikely(base > len))

		base = len;

	xdr->p = (__be32*)(iov->iov_base + base);

	xdr->end = (__be32*)(iov->iov_base + len);

	xdr->iov = iov;

	xdr->page_ptr = NULL;

	return len - base;

}



static int xdr_set_page_base(struct xdr_stream *xdr,

static unsigned int xdr_set_page_base(struct xdr_stream *xdr,

				      unsigned int base, unsigned int len)

{

	unsigned int pgnr;
@@ -991,8 +994,10 @@ static int xdr_set_page_base(struct xdr_stream *xdr, 
	void *kaddr;



	maxlen = xdr->buf->page_len;

	if (base >= maxlen)

		return -EINVAL;

	if (base >= maxlen) {

		base = maxlen;

		maxlen = 0;

	} else

		maxlen -= base;

	if (len > maxlen)

		len = maxlen;
@@ -1011,14 +1016,14 @@ static int xdr_set_page_base(struct xdr_stream *xdr, 
		pgend = PAGE_SIZE;

	xdr->end = (__be32*)(kaddr + pgend);

	xdr->iov = NULL;

	return 0;

	return len;

}



static void xdr_set_page(struct xdr_stream *xdr, unsigned int base,

			 unsigned int len)

{

	if (xdr_set_page_base(xdr, base, len) < 0)

		xdr_set_iov(xdr, xdr->buf->tail, xdr->nwords << 2);

	if (xdr_set_page_base(xdr, base, len) == 0)

		xdr_set_iov(xdr, xdr->buf->tail, 0, xdr_stream_remaining(xdr));

}



static void xdr_set_next_page(struct xdr_stream *xdr)
@@ -1055,12 +1060,9 @@ void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p, 
	xdr->scratch.iov_base = NULL;

	xdr->scratch.iov_len = 0;

	xdr->nwords = XDR_QUADLEN(buf->len);

	if (buf->head[0].iov_len != 0)

		xdr_set_iov(xdr, buf->head, buf->len);

	else if (buf->page_len != 0)

		xdr_set_page_base(xdr, 0, buf->len);

	else

		xdr_set_iov(xdr, buf->tail, buf->len);

	if (xdr_set_iov(xdr, buf->head, 0, buf->len) == 0 &&

	    xdr_set_page_base(xdr, 0, buf->len) == 0)

		xdr_set_iov(xdr, buf->tail, 0, buf->len);

	if (p != NULL && p > xdr->p && xdr->end >= p) {

		xdr->nwords -= p - xdr->p;

		xdr->p = p;

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